This work is concerned with the central neural mechanisms of feeding and drinking behavior in the rat. The controlling influence of humoral agents is being investigated with the specific inhibitor of intracellular glucose utilization, 2-deoxy-D-glucose (2-DG), which has recently been shown to increase food intake in rat and monkey. The recent discovery that angiotensin stimulates thirst when applied directly to the rat diencephalon and limbic system will be pursued to confirm the suggestion of a hormonal control of the thirst produced by hypovolemia. Sensory factors are being studied in rats that feed themselves through chronic intragastric tubes, thus by-passing all head receptors. The by-pass is being combined with denervation of the upper gastrointestinal tract to produce a rat that must regulate intake entirely on the basis of post-absorptive events. An attempt is being made to more clearly define the functions of the lateral hypothalamic area by further analysis of the lateral hypothalamic syndrome of recovery of feeding and drinking that follows damage to this portion of the brain. In addition, the behavioral uses of saliva are being investigated in the rat. The consequences of dryness of the mouth for feeding and drinking are being studied and the uses of saliva in grooming and as a coolant in the heat are being explored. The ontogeny of ingestive behavior is being investigated by studies of the role of saliva in suckling and the effects of early dietary history on ingestion in the adult rat. Lastly, the neuropharmacology of ingestive behavior is being studied with intrahypothalamic manipulations of catecholamines in rats emitting spontaneous meals and drafts.